h23 and h22 blocks are teh same.
the h23 is an h22 with an f22 crank in it.
the h23 vtec is NOT worth it...the one made by honda, th h23a, makes the same HP and 2 ft/lbs of torque more, and thats comparing stock to stock engines.
an h23a1 swap will run in the $900-1300 range usually for the engine tranny and ecu ...and it will put you into mid to high 15s usually, though low 15s may not be too hard to get.
an h22a....will smoke an h23a1....i have an accord wagon with an h22a and raced a prelude si on the freeway, from 70-110mph...i left him about 4 car lengths back...repeatedly.